The PSI Hydraulic Screen Changer allows for filtration of most polymers with minimum disruption during a screen change. PSI Hydraulic Screen Changers feature a patented pressure activated seal that not only seals to 10,000 psi, it eliminates degradation and gels caused in other slide plate type screen changers. PSI Hydraulic Screen Changers are designed to withstand extreme temperatures and filter highly sensitive compounds. Unit can be supplied with either one or three heat zones.